possible sciatic nerve branch damage and contracture post TPLO in rescue dog

[kayjayvet]

So, another strange case.

Almost 9yo MN Husky just rescued by a sweet woman mid October. He had a TPLO done on his RH early September/Late August at the rescue prior to being adopted. When his new mom brought him to me he was already in pretty rough shape.

"Beginning of muscle contracture with severe muscle atrophy RR; painful iliopsoas L>R; myofascial TP's in lumbar paraspinals; even toes are hyperflexed and tight"

Measurements:
Thigh circumference: R 33cm/L 41cm
R stifle extension 130cm (normal 165-170) with muscle/tendon end feel
R stifle flexion 30cm wnl
R hock extension 150cm (normal 170) with muscle/tendon end feel
R hock flexion 40cm wnl
R hip extension 110cm (normal 170) with muscle/tendon end feel

We have been working on lots of stretching and joint mob's from phalanges up to hip. Also added therapeutic laser, acupuncture and weight bearing/neurofacilitation exercises.

The good news - huge improvement in the muscle contracture. ROM in all three joints nearing normal. Hamstrings are still really tight - with hip flexion I can not extend stifle normally (I think that this is just because we haven't been as aggressive with this particular stretch.

BUT - this dog will not use the limb and his toes are still really curled under, despite progress everywhere else. And the atrophy is getting worse bc he is not using the leg. I am wondering if there could possibly be some nerve damage with the TPLO surgery - maybe one of the branches off the sciatic (like the deep fibular?). Sometimes you can see him put his foot down like he wants to use it but it looks like his toes don't work. Owner bought a toe-up hock brace to try but he hates it (OF COURSE). He also does not love his treatment in general (again, very husky like) but I randomly discovered he totally relaxed last visit with tail pulls. Not sure how to put this all together but I am feeling frustrated. Maybe I was expecting improvement too soon? Just want to be realistic with owner and make sure I am not missing anything.

Any ideas? Or similar cases?

Dr. Kelly Hutchison

[David Lane]

There aren't nerve branches that are normally at risk during a TPLO, assuming it was done the standard way. I would wonder more about SDF or DDF contracture as part of whatever other pathology went on to cause such an atypically poor return to function. Do the toes flex at the proximal interphalangeal joint, or the distal, or both? Does it feel like a functional fibrous contracture? What do the SDF/DDF muscle bellies feel like? Any paresis of the hock?

[lehughes]

Very interesting indeed.

I'll start with tagging onto David's comments, and add to try / test extensibility of the SDFT and DDFT. Holding the stifle and tarsus at about 90 degrees at each joint, then extend each toe (at the PIP joint, and then add in the DIP joint). Compare this to the contralateral leg.

Are the reflexes WNL?

The other thing that I think of is a NR impingement up at the L-S junction - in particular because of the reduced extensibility of the 'hamstrings' which could be sciatic nerve. So, to test that, try doing the 'hamstring stretch' with someone pulling the tail. Does that increase the excursion of the stretch? BTW, do the toes curl when you do the hamstring stretch? (I.e. more evidence of nerve root involvement).

What is the rest of the history? Do you know? After the TPLO was the dog just crated? In other words does contracture make more sense than nerve involvement?

Back to you!

Cheers,

Laurie

[kayjayvet]

Honestly, from the beginning I have felt I was primarily dealing with contracture. He does curl his toes at both the proximal and distal joints. I do not have any history - just the assumption that the rescue did not follow up with the dog after surgery and he was put in a crate or run or something like that. I just started to second guess myself when I was getting improvement in hip and stifle extension but seemed so stuck with the toes and hamstrings. And I am also not sure how much of it is also him being a stubborn Husky. I feel like he could reach the floor to place his foot more than he does.

Today I really spent a lot of time with phalanges mob's and stretching/hamstrings and inner thigh stretching and spent more time with the laser and heated blanket in those areas as well. Maybe I just haven't focused on these areas enough.

But, lets say it is contracture, really severe. What are my chances for getting decent enough results that he can use the leg? And what dose that timeline look like? Just want to keep the owner realistic. I have talked to the owner about amputation, just to feel her out, and she really wants to avoid that (of course). My assistant asked me today if you could amputate the foot and fit it with a prosthetic - an interesting idea - not sure.

Thanks for the input.

Dr. Hutchison

[David Lane]

Again, with all the caveats of never having seen the dog....

Based on the description, if it became desperation surgery time, I would transect the SDF and DDF tendons just proximal to the MTP1 joint, aggressively break down any phalangeal fibrosis while you have the benefit of a GA on board, and see what you get after that. Hopefully it will result in a flat foot that will dislikes gravel roads, but will otherwise be pretty functional. If/when it becomes arthritic in the future, examine the utility of an orthotic at that time.